Understanding the DC Reverse Bias Conduction and Breakdown Mechanism in β-Ga₂O₃ Schottky Barrier Diodes

This work, for the first time, reports a voltage ramp rate-dependent modulation of the reverse-bias breakdown of β–Ga<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub>O<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Schottky barrier diodes. Reverse leakage conduction is demonstrated to be limited by thermionic-field electron injection at the Schottky contact and Poole–Frenkel (PF) transport through defect states in the depletion region before transitioning into trap-assisted space charge limited conduction (SCLC). Modulation of the breakdown is shown to be caused by alterations in the transition from PF transport to SCLC, governed by the interplay of electric-field distribution and electron trapping dynamics. Electroluminescence (EL)/photoluminescence (PL) analysis is employed to gain insights into the electric field distribution and involvement of defect states in current conduction. Finally, postfailure electron microscopy is used to understand the dependence of failure on electron trapping and electric field dynamics.